I have an error in Sony Vegas Movie Studio HD 9.0 - I cannot import any audio! I drag them into the player, and it says something like "None of the files dropped into Vegas could be opened" and when I click the import button I get an error saying something like "Error: the file could not be opened. Please make sure that you have read/write per... blah blah blah", so I clicked permissions on the folder and it seemed "locked", so I clicked "unlock" and still it does not work. Would iTunes be affecting this? Please help!

[Moderator edit (MF): removed all caps from subject. No need to shout around here!]